We have studied the interactions of a series of heavy metal ions with synthetic DNA polymers to determine the effects of these ions on buoyant density in the analytical ultracentrifuge. This has enabled us to determine what types of sequences react preferentially with these ions and to determine how they might be most useful in separating natural DNA's of known sequence from one another. In addition, based on these data, one may make some logical predictions about the relative mutagenicity of these agents for loci containing runs of particular nucleotides. Thus, these results should be of special interest to geneticists interested in metal ion mutagenesis.